Editing MultiFinder (section)

==History==
===Background===
The first Macintosh was released in 1984, and Apple's developers made an early decision that the machine's 128 [[Kilobyte|KB]] of [[RAM]] was so limited that they must abandon the application multitasking functionality that Apple had developed for the [[Apple Lisa|Lisa]].{{citation needed|date=October 2021}} As the successive Macintosh hardware models were released with much more RAM being the key feature, new programming techniques were developed as workarounds to allow users to run concurrent applications. Desk Accessories became a staple through the lifespan of System 6; and the Switcher would give way to the MultiFinder, which then became directly integrated into System 7.

====Desk Accessories====
To allow some degree of freedom and to deliver the GUI's promise of interface consistency, the original Macintosh includes [[Desk Accessory#Apple Macintosh|Desk Accessories]], such as a calculator, that can be run concurrently. However, their functionality is deliberately limited in favor of [[RAM]] conservation. In fact, they are device drivers which take advantage of the multitasking system designed for hardware peripheral support. As such, their [[running environment]] is severely restricted. They can only draw a single window, which by default is given a special round-bordered appearance. Although the system software does little to specifically support them, the popularity of Desk Accessories led many application developers to ensure good cooperative multitasking support even from the early days.

====Switcher====
[[Andy Hertzfeld]], one of Apple's original Macintosh software architects, wrote Switcher after seeing [[John Markoff]] use a [[terminate-and-stay-resident program]] on an IBM PC in October 1984. By the end of the year he had a working prototype, and he soon demonstrated it in public.<ref>{{cite web|url=http://macgui.com/usenet/?group=8&id=368|title=Mac GUI :: Switching Mac Applications|website=macgui.com|access-date=February 15, 2019}}</ref>  Both [[Microsoft]] and Apple wanted to purchase the utility. Hertzfeld chose the latter because of his belief that Switcher should be bundled with the Macintosh system. Apple offered more money ({{US$|100000}} plus royalties) and the company planned to ship Switcher with the [[Macintosh 512K]]. The first official version of Switcher appeared in April 1985.<ref name="folklore">{{Cite web |url=https://www.folklore.org/StoryView.py?story=Switcher.txt |title=Switcher |last=Hertzfeld |first=Andy |website=Folklore.org}}</ref>

Switcher works by designating a number of fixed slots in memory into which applications could be loaded. The user can then switch between these applications by clicking a small button on the top of the [[menu bar]]. The current application horizontally slides out of view, and the next one slides in. Though awkward, this approach does fit well with the existing system's [[Mac OS memory management|memory management]] scheme, and applications need no special programming to work with Switcher.<ref>{{cite web|url=http://macgui.com/usenet/?group=8&id=1113|title=Mac GUI :: Switcher hints|website=macgui.com|access-date=October 9, 2017}}</ref> This early work on Switcher led to the development of MultiFinder by Apple system software engineers Erich Ringewald and [[Phil Goldman]].

Microsoft saw Switcher as especially benefiting the company's highly memory-optimized Macintosh applications{{r|folklore}} so the utility was shipped with [[Microsoft Excel|Excel]]. Microsoft stated that using multiple applications with Switcher was preferable to a single [[integrated software]] application like [[Lotus Symphony (DOS)|Lotus Symphony]].<ref name="pournelle198509">{{cite news | url=https://archive.org/stream/byte-magazine-1985-09/1985_09_BYTE_10-09_Homebrewing#page/n329/mode/2up | title=PCs, Peripherals, Programs, and People | work=[[Byte (magazine)|Byte]] | date=September 1985 | access-date=March 20, 2016 | author=Pournelle, Jerry | pages=347}}</ref> By 1987, ''[[Compute!]]'s Apple Applications'' reported that "many Macintosh owners are comfortable only when using more than one application at a time. Switcher and desk accessories are the two most common examples of that philosophy".<ref name="caa198712">{{cite news | url=https://archive.org/stream/COMPUTEs_Apple_Applications_Vol._5_No._2_Issue_6_1987-12_COMPUTE_Publications_US#page/n9/mode/2up | title=Information On A Card | work=Compute!'s Apple Applications | date=December 1987 | access-date=August 18, 2014 | pages=6}}</ref> ''[[PC Magazine]]'' said that Switcher used too much of the system's precious little RAM and was not reliable enough.<ref name="The new seekers"/>

====Multi-Mac====
Multi-Mac is another application switching utility designed specifically for the Macintosh 512K, though it is more known for its mysteriousness. Showing up sometime in late 1985, after the introduction of Switcher, and being credited as being made by ''Jwa van der Vuurst'' with a copyright by ''Aubrac Systems'', it makes over 200 direct calls to undocumented addresses in the Macintosh ROMs.<ref>[https://web.archive.org/web/20040413221517/http://homepage.mac.com/senorwences/servant_page/servant_multimac.html Multi-Mac - Macintosh Servant]</ref> This led to the accusations that ''Jwa van der Vuurst'' was merely an alias and that the program was actually from someone that worked at Apple and had significant knowledge on the Macintosh's inner workings. The app itself adds a second apple menu on the right side of the menu bar which displays all currently running application and allows switching between them. It also allows adjusting the applications' memory allocation size, disk cache and adds background multi-threaded copying similar to [[Connectix|Speed Doubler's]] and [[Mac OS 8]]'s improved copy function.<ref>[https://web.archive.org/web/20190711202715/http://school.anhb.uwa.edu.au/personalpages/kwessen/web/stories/EarlyMacStories.html#multitasking Multitasking and the Mysterious Multimac - Stories of Early Mac]</ref>

====Servant====
Servant was another attempt by Andy Hertzfeld at multitasking on the Macintosh, intended to solve Switcher's shortcomings. Released in September 1986, it was effectively a Finder, Switcher and [[ResEdit]] combined into one tool for the [[Macintosh Plus]].<ref>[https://web.archive.org/web/20040413223524/http://homepage.mac.com/senorwences/servant_page/servant_servant_intro.html Servant - Macintosh Servant]</ref> Its file manager is unusual due to its lack of a scrollbar, instead requiring to hold and drag the window background like a modern map app. One of its most interesting features is the first known implementation of wallpapers on the Macintosh, allowing users to replace the default grey background with [[MacPaint]] or ThunderScan images.<ref>[https://web.archive.org/web/20040413223131/http://homepage.mac.com/senorwences/servant_page/servant_servant_finder.html Finder - Macintosh Servant]</ref> In comparison to Switcher, Servant allows users to open apps as they see fit instead of requiring you to select which apps you want to run first, then launching them inside Switcher. Switcher also has a primitive ability to recover from application crashes as well as force quit stuck applications that are no longer responding.<ref>[https://web.archive.org/web/20040404051048/http://homepage.mac.com/senorwences/servant_page/servant_servant_switcher.html Switcher - Macintosh Servant]</ref> The result is a user experience more intuitive than Switcher. While Servant's resource editing features are not as full featured as ResEdit, it does allow editing file icons.<ref>[https://web.archive.org/web/20040413224430/http://homepage.mac.com/senorwences/servant_page/servant_servant_resedit.html ResEdit - Macintosh Servant]</ref>

===MultiFinder===
{{see also|Mac OS memory management}}
MultiFinder, known before its release as "Juggler",<ref>{{cite magazine
| url = https://archive.org/stream/MacWorld_8709_September_1987#page/n13/mode/2up
| title = Mac Bulletin
| magazine = MacWorld
| date = September 1987
}}</ref> was introduced on August 11, 1987.<ref name="Mac GUI :: MultiFinder Announced"/> It is simply a way for windows from different applications to coexist by using a cooperative application layering model. Its initial release is able to handle only two concurrent applications, one of which runs in the background;<ref name="The new seekers">{{cite magazine| magazine=[[PC Magazine]] | title=The new seekers: Hypertext comes of age|url={{Google books|KU7dCBpP7fsC|page=108-109|plainurl=yes}}|page=109|date=November 24, 1987 | access-date=March 8, 2019}}</ref> and later releases allow many more concurrent applications. When an application is activated, all of its windows are brought forward as a single layer. This approach is necessary for [[backward compatibility]] with many of the windowing [[data structure]]s that were already documented. MultiFinder also provides a way for applications to supply their memory requirements ahead of time, so that MultiFinder can allocate a chunk of RAM to each according to need. This scheme, while functional, has severe limitations which cause many problems for users. Virtual memory was only available to contemporary Macs with a PMMU chip (Mac II-class machines required) and an extension named Virtual from [[Connectix]].<ref name="Orchestrating applications" /> Apple eventually provided virtual memory with the introduction of System 7.<ref>{{Cite book|title=Inside Macintosh: Memory|publisher=Addison-Wesley Publishing Company|year=1992|isbn=0-201-63240-3|location=Reading, Massachusetts|pages=3–5}}</ref>

Later in 1987, System 6 engineer Erich Ringewald's desire to solve these architectural problems altogether would bring him to defiantly cofound and lead the [[Taligent#Pink|Pink]] project as the intended future of a new MacOS,<ref name="Apple's First Stab">{{cite web | first=Tom | last=Hormby | date=April 27, 2014 | work=Low End Mac | title=Pink: Apple's First Stab at a Modern Operating System | url=http://lowendmac.com/2014/pink-apples-first-stab-at-a-modern-operating-system/ | access-date=February 1, 2019}}</ref> and then become chief software architect at [[Be Inc.]] to design [[BeOS]] in 1990.<ref name="Be Newsletter, Vol 3">{{cite magazine | magazine=Be Newsletter | title=Be Newsletter | volume=3 | issue=8 | date=March 25, 1998 | url=https://www.haiku-os.org/legacy-docs/benewsletter/Issue3-12.html | access-date=February 1, 2019}}</ref>

With the release of [[System 7 (Macintosh)|System 7]], the MultiFinder extension was integrated with the operating system, and it remained so in [[Mac OS 8]] and [[Mac OS 9]]. However, the integration into the OS does nothing to fix MultiFinder's inherent idiosyncrasies and disadvantages.<ref name="Orchestrating applications"/> These problems were not overcome in the mainstream Macintosh operating system until the MultiFinder model was abandoned with the move to a modern [[preemptive multitasking]] [[Unix]]-based OS in [[Mac OS X]]. Two utilities, CPU Doubler and Peek-A-Boo, did implement a form of priority based [[Scheduling (computing)|task scheduling]] in the classic Mac OS, though they were unable to solve its other issues, like the lack of [[protected memory]].<ref>[https://tidbits.com/2000/05/15/inspecting-gadget/ Inspecting Gadget - TidBITS]</ref><ref>[https://www.youtube.com/watch?v=DkNuO2KXv-8 How I Hacked a 90's Mac Kernel: CPU Doubler, a QL-like Task Scheduler/Task Manager - YouTube]</ref>